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The effect of constant height bracket placement on marginal ridge levelling using digitized models
1Department of Orthodontics, Université de Genève, Switzerland. carlos.suarez@medecine.unige.ch
European Journal of Orthodontics
|June 3, 2009
Summary
Accurate bracket placement is crucial in orthodontics. This study found that a fixed-value bracket placement protocol on digital models often worsened marginal ridge levels, particularly for premolars and molars.
Area of Science:
- Orthodontics
- Dental Technology
Background:
- Accurate bracket placement is essential for effective orthodontic treatment.
- Proper initial positioning can prevent the need for later adjustments like archwire bends or bracket repositioning.
- The built-in prescription of orthodontic brackets needs precise placement to function correctly.
Purpose of the Study:
- To evaluate the impact of a bracket placement protocol using fixed measurements from incisal edges and occlusal surfaces.
- To assess the leveling of marginal ridges after applying this protocol on digitized dental models.
- To investigate the predictability of orthodontic treatment outcomes using virtual set-up software.
Main Methods:
- Utilized OrthoCAD virtual set-up software for digital simulation.
- Employed 3M MBT Victory Series brackets (0.022 inch) and a 0.019 x 0.025 inch stainless steel archwire.
- Analyzed 42 digitized dental models, comparing pre- (T1) and post- (T2) treatment marginal ridge heights using a paired t-test.
Main Results:
- The majority of marginal ridge points showed deterioration during the digitized treatment prediction compared to the initial state (T1).
- Statistically and clinically significant changes (P < 0.05) were observed in the marginal ridge heights of upper premolars and lower molars.
- Tooth facial contour variability was identified as a significant factor influencing the results.
Conclusions:
- The tested bracket placement protocol, relying on fixed values, did not consistently achieve optimal marginal ridge leveling in digital simulations.
- Variations in tooth anatomy, specifically facial contour, significantly impact the effectiveness of standardized bracket placement.
- Further research is needed to refine digital bracket placement protocols to account for individual tooth morphology.
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